It will never cease to amaze me how people manage to so thoroughly miss the point of Spec Ops: The Line or think that they are experiencing the game to its fullest while doing everything in their power to go against it, only to be let down when, surprise surprise, the game designed to point out everything troubling about linear modern warfare shooters, asks that you be linear about playing it.
Sorry if I seem cross, for I don't mean to; you're probably one of the more reasonable people I've seen disagree with The Line. It's just that I think you're going about the game in entirely the wrong way.
The Line is purposefully constructed to be a parody and satire of everything that Yager (a German company) feels is wrong or questionable about American, modern warfare shooters. It honestly seems like you've cut yourself off from anyone talking about the game, period, though. You're looking at it in a vacuum, and it does not exist in one in the least.
I'l get to the point. Look, when you play Modern Warfare 3 or Black Ops or whatever, your go through a series of rooms, kill all the dudes in the room, and advance to the next one. There are set pieces and the like, sure, but for the most part, you advance by killing dudes and walking past them. All the while, you witness some utter military pornography and a ceaseless string of jingoistic choruses shouting "AMERICA, FUCK YEAH!"
And it's always the right thing to do. You are always the good guy (read: the Americans/Westerners) always fighting the bad guys (read: terrorists or Russians), and no matter how badly things might go on a mission, it all works out in the end. Good guys win, bad guys lose, everything's hunky dory.
In Spec Ops, you do much the same thing (kill dudes, walk past them), but rarely is it ever the right thing to do, even temporarily. You try to figure out what's going on in Dubai, and you murder scared people who were hiding from the Damned 33rd. You try to rescue Gould and civilians die. You try to help the CIA agent and condemn everyone in Dubai to die of thirst. The entire thing is set up as a means of examining why it's so weird that killing everyone who isn't you is, from a gameplay standpoint, the right thing to do.
Think about how many times Walker says "I did what I had to do." He says it quite a lot when questioned about his decisions to use white phosphorus, destroy Dubai's water supply, and murder all the well-meaning American troops who were trying to stop him. The player, upon having the game question their actions, probably says something similar, such as "I couldn't progress any other way" or something.
Of course you couldn't. That's the fucking point. In any modern warfare game, the linear path of gameplay is always the right thing to do. In The Line, it almost never is. Other game congratulate you for following their path - The Line asks you what the hell is the matter with you that you're okay with screwing up everything the Dubai people have in order to satisfy some narrative curiosity, or to have fun.
This might seem surprisingly simple, but considering how masturbatory the triple-A game industry is and how bloated with modern warfare shooters it is, I think it isn't as surprising as one would initially suspect.